<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<div id="app">
			<input v-model='s' /><br>
			<button @click="ok=str.toUpperCase()">大写</button>
			<button @click="ok=str.toLowerCase()">小写</button>
			<div>
				{{ shuchu }}
			</div>
		</div>
		<script type="text/javascript">
			let app =new Vue({
				el:"#app",
				data:{
					s:'',
					shuchu:""
				}
			});
		</script>
	</body>
</html>
